This study is a descriptive research study attempted to identify factors influencing depression of new nurses, focusing on job stress, self-efficacy, resilience, and social support factors of new nurses. The subjects of this study were 174 new nurses with less than one year of nursing experience, who worked at five university hospitals in the metropolitan area. A self-report questionnaire was used for the data collection of this study. The collected data were subjected to stepwise multiple regression to analyze the factors affecting depression using the SAS 9.4 program. As a result of the study, the average score of depression of the subjects was 13.01 out of 80, Factors influencing the subject's depression were identified including job stress(p<.001), self-efficacy(p=.044), resilience(p=.013), social support(p=.012), work department(p=.021), and work type(p=.001). It was found that the higher the job stress of the subject, the higher the degree of depression, while the higher the self-efficacy, resilience, and social support of the subject, the lower the degree of depression. In this study, it was confirmed that job stress, self-efficacy, resilience, and social support were factors influencing the depression of new nurses. In order to prevent depression of new nurses and actively manage with depression, it is suggested that arbitration programs for new nurses will be needed to reduce job stress of new nurses, strengthen self-efficacy, resilience and social support. It is also thought that strategies supporting for new nurses at the organizational level, such as the establishment of various social support systems, are needed

In this paper, the mechanical properties of glass fiber reinforced plastic (GFRP) rebar, which has been applied as an concrete reinforcement, and produced carbon fiber reinforced plastic (CFRP) grid were compared to develop a concrete reinforcement material with excellent mechanical properties. In addition, the mechanical properties of CFRP prepared with each molding process were evaluated. Three molding processes were evaluated: prepreg oven bagging, reaction injection molding (RIM), and pultrusion. The tensile strength of the CFRP grid prepared through pultrusion was 2.85GPa, the elastic modulus was 169.81GPa, and the strain was 1.68%, which was 2.85 times better in tensile strength, and 2.83 times better in elastic modulus compared mechanical properties of GFRP rebar. The strain was confirmed to be equivalent to GFRP rebar.

The quality and antioxidant characteristics of apios (Apios americana Medikus) according to different harvest periods and steaming treatment were investigated. The quality and antioxidant characteristics of apios were significantly different depending on harvest periods. Total starch contents was higher in 1st harvesting period as 62.32 g/100 g than other harvesting period. The water binding capacity and water solubility index was higher in 1st harvesting period as 228.65 and 11.29% than other harvesting period. The sucrose and total free sugar contents were 3.64~8.67 and 4.49~9.54 g/100 g, respectively. Total polyphenol and flavonoid contents of apios was the highest 2nd and 4th harvesting period at 4.21 mg GAE/g and 611.11 μg CE/g, respectively. DPPH radical scavenging activity was higher in 1st harvesting period as 84.96 mg TE/100 g than other harvesting period, and decreased as the harvest periods were delayed. ABTS radical scavenging activity and ferric-reducing antioxidant power were 43.81~47.89 mg TE/g and 231.20~264.07 mM/100 g, and increased to 50.58~51.44 mg TE/g and 342.55~384.29 mM/100 g after heat treatment. As a result, it is thought that studies on change of quality and physicochemical characteristics according to cultivation characteristics should be preceded for cultivation stability of apios.

In vitro digestibility and protein digestibility corrected amino acid scores (PDCAAS) were investigated to verify the availability of protein in various Rhizopus oligosporus fermented products of domestic soybean (Glycine max L.) cultivars. Danbaegkong (DBK), Daepung (DP), Daewonkong (DWK), Saedanbaek (SDB), Seonyu (SY), and Cheongja4ho (CJ4) were used as raw samples, which were fermented using commercially available Rhizopus oligosporus for 48 h. All cultivars showed increased crude protein content after fermentation. The crude protein content of DBK and SDB was significantly higher than that of the other samples (55.12% in DBK and 54.22% in SDB) (p<0.001). CJ4 had the highest alanine content of 28.88 mg/g (p<0.001), and no significant difference in cysteine content was detected among the cultivars. In most of the fermented samples, the in vitro digestibility was 0.9 or higher, indicating high protein in the fermented samples. However, it is considered that restrictions on digestion are low. In DWK, the amino acid content and PDCAAS, which together indicate protein quality, were 0.917 and 0.855, respectively, confirming that it was the best cultivar to provide the raw material for fermentation. In conclusion Rhizopus oligosporus fermented soybean products can be considered a prospective source of protein with high utility value.

To enhance the bioavailability and bioactivities of mixed herbal medicines (RW), they were fermented with lactic-acid bacteria isolated from kimchi into postbiotics (FRW). Then, from the results of the 16s rRNA sequencing analysis, lactic acid bacteria isolated from kimchi were identified to be of two species, namely Lactobacillus sakei and Leuconostoc mesenteroides. The FRW prepared from the RW were extracted using hot water (HW) and 70% EtOH (EtOH) for comparison of their macrophage-stimulating activities. Based on a comparison of the activities of the FRW extracts, nitric oxide (NO) production of HW was significantly higher than that in EtOH. An analysis of the chemical properties of the extracts showed that HW had higher contents of neutral sugar and uronic acid than EtOH as well as contained a large amount of glucose. In addition, crude polysaccharide (CP) was prepared to enhance the macrophage-stimulating activity. The FRW-CP not only secreted immunostimulatory mediators but also increased the expression of immunostimulatory genes (iNOS, TNF-α, MCP-1, and IL-6). The fractionated FRW-CP contained about 90% neutral sugars, and these sugars were mainly composed of glucose, galacturonic acid, and arabinose. Thus, FRW prepared by fermentation of RW with kimchi lactic acid bacteria were found to be immunostimulatory modulators.

The research was based on long-term studies on the major physico-chemical and hydrological factors and zooplankton community dynamics in the Hwang River. We had 341 times survey and collected zooplankton samples in the Hwang River of mid-Nakdong River from 1995 to 2013. We identified 97 zooplankton species, including 77 rotifers, 16 cladocerans, and 4 copepods. The total zooplankton abundance and species diversity were shown distinctive temporal variation (ANOVA, p<0.001). Annual average of zooplankton population density was 58.4±3.2 ind L-1 (n=341) and the lowest was 17.0±3.8 ind L-1 (1996, n=20), while the highest was 151.5±32.3 ind L-1 (2010, n=22). For zooplankton, small rotifer groups (e.g., Keratella sp., Brachionus sp., Trichotria sp.) dominated the study site for 19 years survey. Statistical analysis revealed that there were positive relationships with SiO2 (p=0.002) and water level (p<0.001) for the high abundance of rotifer community. There were considerable variations both the total cladocerans population and the number of cladocerans’ species concerning annual precipitation. Despite the appearance of various zooplankton in the Hwang River, the mean population density remained low. Due to the lateral structures in the Nakdong River, the downstream basin of the Hwang River is inevitably affected. The zooplankton community in our study site is considered to be mainly influenced by external factors that can stably increase and maintain the volume of the water body and internal factors that induce an increase in food sources through the inflow of nutrients into the water body.

Quality standards of activated carbon for gas-phase applications have been deleted from the Korean national standard list since 2007, and the iodine adsorption test is the only measure currently used for quality assurance. This study was performed to propose a suitable test method and a quality standard for gas-phase activated carbon. The "1/2 saturated vapor adsorption" test has been developed as a simple and convenient method to determine the adsorption capacity of activated carbon. In this study, the developed test method was evaluated using model VOCs including toluene, methyl ethyl ketone (MEK), and ethyl acetate (EA). A virgin activated carbon revealed adsorption capacities of 344mg/g, 322mg/g, and 328mg/g for toluene, EA, and MEK, respectively, and the adsorption capacity for a mixture of the three VOCs was 334 mg/g. When a regenerated activated carbon was applied, the adsorption capacities dramatically decreased to 62 mg/g, 52 mg/g, and 61 mg/ g for toluene, EA, and MEK, respectively. In addition, the 1/2 solvent vapor adsorption tests using 13 different specimens of activated carbon showed that their capacities were closely related to the iodine adsorption numbers, and this study suggested the adsorption capacity of 300 mg/g as a new quality standard. The novel test method and its standard may help to guarantee the quality of gas-phase activated carbon used for VOCs abatement processes.

Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon’s Hʹ values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of subsample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.

붕어(무게 28.1±3.7 g, 길이 10.0±1.0 cm)에 0, 2.0×104, 2.0×105, 2.0×106, 2.0×107 CFU/ml의 Aeromonas hydrophila를 주사 후 2주간 실험을 실시하였다. A. hydrophila로 인위감염한 Carassius carassius의 2주 뒤 반수치사농도는 19.776×105 CFU/ml이었다. 혈액학적 지표에서는 A. hydrophila에 의해 혈색소와 적혈구 수가 유의하게 감소한 반면, 적혈구 용적은 유의적 변 화가 없었다. 마그네슘, 칼슘과 같은 혈장 무기 성분은 유의적으로 감소하였다. 유기 혈장 성분 에서 A. hydrophila 인위감염에 의해 혈장 포도당과 콜레스테롤이 유의하게 증가한 반면, 총 단 백질은 유의하게 감소하였다. 혈장 효소 성분인 ALP는 A. hydrophila 인위감염에 의해 유의하 게 증가하였다. 본 연구의 결과는 C. carassius에 대한 A. hydrophila의 인위감염이 치명적인 병원성 세균으로 혈액학적 성상 및 혈장 성분에 유의한 생리학적 변화를 유도하였음을 의미 한다.

한우 개량에 있어서 추정된 유전체육종가와 정확도는 선발에 중요한 지표로 사용되며, 최근 육종가 추정에 있어 정확도의 신뢰도를 높이기 위해 혈통과 유전체정보를 이용한 연구가 활발히 진행되고 있다. 따라서, 본 연구는 가계 내 유전체정보량에 따라 유전체정보가 미포함된 개체의 정확도 변화를 확인하고자 동일한 부모를 가진 한우 10두로 구성된 전형매 가계 3개를 수집하였으며, 각 가계 별로 유전체정보량을 10두, 8두, 6두, 4두, 2두씩 무작위로 선별하여 5가지의 검정집단으로 가정한 후 참조집단 14,225두를 이용하여 single step genomic best linear unbiased prediction (ssGBLUP)을 통해 genomic estimated breeding value (GEBV) 및 정확도를 추정하였다. 각 검정집단과 참조집단의 혈통 및 유전체정보 를 이용하여 H-matrix를 구축하였고, BLUPF90 program을 사용하여 도체중, 등심단면적, 등지방두께, 근내지방도의 GEBV 및 정확도를 추정하였 다. 첫 번째 가계를 대상으로 살펴보면, 검정집단에서 유전체정보를 보유하고 있는 10두의 GEBV 평균 정확도는 도체중 0.734, 등심단면적 0.717, 등지방두께 0.712, 근내지방도 0.745로 추정되었다. 이후 2두씩 무작위로 유전체정보를 제거하여 추정한 GEBV 정확도를 살펴보면, 유전체정보를 보유한 개체의 경우 정확도의 변화가 나타나지 않았지만, 유전체정보가 미포함된 개체의 정확도가 평균 0.114 ~ 0.168 낮게 추정되었다. 가계 내 유전체정보량에 따른 유전체정보가 미포함된 개체의 GEBV 평균 정확도는 도체중 0.604 ~ 0.576, 등심단면적 0.6 ~ 0.573, 등지방두께 0.599 ~ 0.572, 근내지방도 0.607 ~ 0.578로 평균 0.009씩 감소하는 것을 확인하였다. 이를 통해 가계 내 유전체정보량이 개체 별 유전체정보 유무와는 상관없이 GEBV의 정확도 추정에 큰 영향이 없었으며, 신뢰도가 높은 GEBV 추정을 위해서는 개체 별 유전체정보의 유무가 더 큰 영향을 미친다는 것을 확인하였다.

붕어(무게 42.4 ± 9.0 g, 길이 15.0 ± 1.0 cm)를 96시간 동안 0, 5, 10, 20, 40 및 80 mg Zn2+/l의 수 인성 아연에 노출시켰다. 수인성 아연에 노출된 붕어의 96시간 반수치사농도(LC50)는 51.58 mg Zn2+/l였다. 혈액학적 지표에서 48시간에 40 mg Zn2+/l 농도에서 RBC 수치가 유의하게 감소 한 반면, 헤마토크릿은 아연 노출에 의해 유의하게 증가하였다. MCV (μl)와 MCH (pg)는 40 mg Zn2+/l 농도에서 48시간에 유의하게 증가하였다. 칼슘, 마그네슘, 포도당, 콜레스테롤, 총 단백질 및 ALT와 같은 혈장 성분은 아연 노출에 의해 크게 변화되었다. 본 연구의 결과는 붕어에 대한 아연 노출이 독성으로서 혈액학적 매개변수 및 혈장 성분의 유의한 생리학적 변화를 유발함을 시사한다.

본 실험은 붕어(Crucian carp, Carassius carassius)(무게 39.7±3.1 g, 전장 14.8±0.5 cm)의 수인 성 니켈 0, 10, 20, 40, 80 및 160 mg Ni2+/l 농도로 96시간 급성 노출을 실시하였다. 수인성 니 켈에 노출된 붕어의 반수치사농도(LC50)는 117.69 mg Ni2+/l으로 나타났다. 혈액학적 성상에서 RBC count는 수인성 니켈 96시간 급성 노출 중 48시간에서 유의적으로 증가한 반면, 96시간에 서 유의적 감소가 나타났다. MCV와 MCH는 96시간에서 80 mg Ni2+/l 농도에서 유의적으로 증 가했다. Calcium, magnesium, glucose, cholesterol, total protein, AST, ALT 및 ALP 와 같은 혈장 성분은 수인성 니켈 노출에 의해 유의적 변화가 나타났다. 이 연구의 결과는 수인성 니켈 노출 에 따른 붕어의 생존율, 혈액학적 성상 및 혈장 성분의 변화를 확인하고 이는 수인성 니켈의 독성에 의한 것으로 판단했다.

After liquid culture of Phellinus baumii (P. baumii) mycelium (LPBM) was prepared, LPBM was fractionated into A∼E fraction (A; hot-water extract of liquid culture including mycelia, B; crude polysaccharide of A, C; hot-water extract of mycelia, D; crude polysaccharide of C, and E; crude polysaccharide of culture broth) to evaluate for possibility as functional materials with immunostimulatory activity. In macrophage stimulatory activity, E fraction as postbiotics significantly increased secretion of NO and IL-12 from RAW 264.7 cells. Next, when the splenocytes of C3H/HeN mice were primary cultured, E fraction showed significantly mitogenic activity with enhancing mitogen-related cytokines (IFN-γ and TNF-α) production from splenocyte. E fraction also potently stimulated GM-CSF production from Peyer’s patch cells as well as Peyer’s patch-mediated bone marrow cell proliferation. In addition, the immunostimularoy E fraction contained neutral sugar (73.8%), uronic acid (10.6%), protein (7.8%), and polyphenol (7.5%), and mainly consisted of glucose (39.1%), galactose (21.7%), mannose (11.1%), galacturonic acid (9.9%), and arabinose (8.9%) as component sugars. In conclusion, it was demonstrated that postbiotics including exopolysaccharide fractionated from liquid culture of the P. baumii mycelium could enhanced immunostimulatory activity.

국산재 원목 공급은 국유림과 민유림에서 이루어지고 있다. 하지만 산림벌채를 수반하는 원목 공급에 대하여 일부 환경단체들은 산림환경의 파괴에 대한 우려를 제기하고 있다. 반면에 산림청과 원목 생산자는 시장의 안정과 목재산업을 보호를 위해 안정적인 국산재 원목 공급의 필요성을 주장하고 있다. 따라서 이 연구의 목적은 국산재 원목 공급정책의 변화가 국산재 원목 시장에 미치는 영향을 분석하는 것이다. 이를 위해 국유림 원목 공급량의 변화가 국산재 원목 시장에 미치는 영향을 국산재 원목 수급 탄성치를 이용하여 분석하였다. 그 결과, 국유림 원목 공급량이 10%, 30%, 50% 감소하는 시나리오에 따라 국산재 원목 시장의 균형가격은 상승하였고 그 범위는 7.56% (114천원/㎥)∼41.05% (150천원/㎥) 나타났다. 하지만 균형 물량은 감소하였고, 그 범위는 불과 -0.22% (3,101천㎥)∼ -0.04% (3,107천㎥)로 분석되었다. 이 연구가 주는 함의는 적은 수준의 공급량 감소에도 원목 생산자의 이익은 증가할 수 있다는 것이다. 하지만 원목 공급량 감소에 따른 가격의 상승은 원목 수요자에게는 상대적으로 부담이 가중될 것이다. 따라서 원목 수급량 변화에 가격이 민감하게 반응하는 국산재 원목 시장의 특성을 고려하면 원목 시장의 안정을 위해서 공급량을 감소시키는 정책은 숙고할 필요가 있다.

최근 GPS에 기반한 위치 수집 기술의 발전과 스마트폰과 같은 GPS를 탑재한 디바이스의 폭발적인 증가로 사람, 차량, 선박, 항공체와 같은 움직이는 물체의 지리적 위치에 대한 엄청난 양의 데이터가 실시간으로 수집되고 있다. 이는 사물의 움직임과 관련된 중요한 학문적 및 실용적 가치를 가지고 있다. 이와 같은 데이터를 분석하기 위한 데이터 마이닝 방법 또한 함께 발전하고 있으며 연구자들은 궤적 데이터를 활용하여 도시에서 일어나는 이동 현상과 도시를 구성하는 장소 간의 관계 등을 탐색함으로써 다양한 도시 문제에 대한 해결방안을 제시하고 있다. 궤적은 다양한 물체의 움직임을 추적할 수 있는 만큼 그 활용 분야와 목적 역시 매우 다양하여 도시 계획, 교통, 행동생태학, 공공안전, 이상 및 위반 탐지, 감시 등과 같은 분야에서 널리 활용되고 있다. 특히 최근 데이터 마이닝 방법론과 딥러닝 기술의 발전으로 궤적 데이터 분석에 다양한 분석방법이 융합적으로 접목되어 의미 있는 연구결과 도출되고 있어 이에 대한 체계적 분석이 필요하다. 이러한 배경하에 본 연구는 궤적 데이터를 활용한 국내외 약 150여 편의 연구를 응용분야 및 활용방법론 별로 구분하고, 응용분야별, 궤적 데이터 분석 방법론별 최근 동향을 분석하였다. 이는 향후 궤적 데이터에 적용가능한 방법론 탐색, 궤적 데이터 분석과 관련된 구체적 사례 탐색, 궤적 데이터를 활용한 응용서비스 도출의 자료로 활용될 수 있을 것으로 사료된다.

국내 유통 중인 콜라겐 제품 120건을 대상으로 중금속 4종(납, 카드뮴, 비소, 수은) 함량에 대해 조사하였다. 수 은은 금아말감화법을 이용한 수은분석기로 분석하였고 납, 카드뮴, 비소는 ICP-OES를 이용하여 분석하였다. 검사 결 과 납의 평균 함량은 0.097±0.055 mg/kg이었고 건강기능 식품, 기타가공품, 음료류, 과·채가공품에서 각각 평균 0.108±0.052mg/kg, 0.084±0.053 mg/kg, 0.131±0.047 mg/ kg, 0.149 mg/kg 농도로 검출되었다. 카드뮴의 평균 함량 은 0.026±0.011 mg/kg이었으며 검출된 제품은 모두 건강 기능식품이었다. 비소의 평균 함량은 0.097±0.048 mg/kg 이었고 건강기능식품, 기타가공품, 과·채가공품에서 각각 평균 0.091±0.055 mg/kg, 0.133 mg/kg, 0.086 mg/kg 농도 로 검출되었다. 수은의 평균 함량은 0.0025±0.0016 mg/kg 으로 건강기능식품, 기타가공품, 과·채가공품, 캔디류에서 각각 평균 0.0012 mg/kg, 0.0028±0.0018 mg/kg, 0.0013 mg/kg, 0.0031 mg/kg 농도로 검출되었다. 중금속 기준·규 격이 있는 음료류(납 0.3 mg/kg, 카드뮴 0.1 mg/kg) 및 캔 디류(납 0.2 mg/kg)는 모두 기준 이하로 검출되어 적합하 였다. 기준·규격이 없는 제품도 국내외 식품의 중금속 기 준과 보고된 식품 중금속 함량과 비교하였을 때 비교적 안전한 수준이라고 판단되었다.

Climate change due to global warming causes a rise in atmospheric air temperature to rise and extreme shift in precipitation patterns. Carbon dioxide (CO2) is widely known as one of the major cause of global warming and accounts for about 72% of total greenhouse gas emissions. Agriculture is more vulnerable to climate change than other industries. Many studies have been conducted to investigate how agroecosystems, both natural and controlled, will respond to the rising level of CO2. Studies on the responses of crops and agricultural environments to climate change are crucial in predicting changes in agro-ecosystems. Research facilities for various types of CO2 treatment have been developed. The representative research facilities are SAR (Soil-Plant-Atmosphere-Research), OTC (Open Top Chamber), FACE (Free Air CO2 Enrichment System), and TGC & CTGC (Temperature Gradient Chamber & CO2-Temperature Gradient Chamber). Therefore, this study reviewed research data and their application in agriculture.

Objectives of this study were to propose an optimal fertilization method of Chlorella and to evaluate its effects on growth of green pepper. Chlorella fusca strain was propagated and used in the experiment. As for treatment, drenching method (DM), foliar fertilization (FF), drench and foliar fertilization combination (DM + FF), and untreated control (CO) were used. Plant height of green pepper was higher in the CO treatment than in chlorella fertilized treatments. Chlorella fertilization inhibited stem growth of green pepper. Chlorophyll contents of green pepper leaves were higher in the DM + FF treatment. Yields were the higher in DM and DM + FF treatments than in other treatments. Vitamin C content was the highest in the DM + FF treatment. These results showed that Chlorella fertilization could increase the growth, yield, and bioactive substance content of green pepper. The Chlorella fertilization method could be applied to other crops. By applying this technology to the farmer, it is possible to increase income and supply healthy and safe high-quality agricultural products to consumers.

Pleurotus species are the most consumed and cultivated mushrooms in Korea. Although oyster mushrooms (P. ostreatus) can be cultivated automatically, their storability is slightly lower than that of king oyster mushrooms (P. eryngii) and winter mushrooms (Flammulina velutipes); therefore, the export proportion of oyster mushrooms is very low. Since Korean mushrooms are highly preferred across Southeast Asian, the export of oyster mushrooms in the form of complete substrates is expected to be more promising than that of fresh mushroom. Here, 1 and 2.5 kg complete substrates of P. ostreatus ‘Soltari’ and P. sajor-caju ‘Sambok’ were prepared and stored at different temperature from 0 to 15°C for 10 days. Thereafter, the formation of fruiting bodies was induced. Since the 2.5 kg complete substrates required 70 days of incubation, their mycelia were at an advanced age and their fruiting bodies did not grown normally. When 70%-incubated complete substrates were stored at 5–10°C, the growth was faster and more uniform and stable fruiting bodies were formed. Export test of complete substrates to Vietnam using distribution containers set at 0°C and 15°C revealed that the growth period was shortened by 1–2 days when the distribution containers were set at 15°C and the yield of ‘Soltari’ increased by approximately 10%. In addition, even though the yield of ‘Sambok’ was similar between treatments at 0°C and 15°C, the quality of fruiting bodies from 15°C-distributed complete substrates was much better than that of those from 0°C-distributed substrates.

This article examines the variations found in the use of ‘eung’ and ‘eo’ in TV dramas and their scripts. Five series of TV drama televised during the 2010s were used as the data for this study, and 3,202 tokens of {eung} and {eo} were collected from the data. Statistical analyses were conducted using Goldvarb X and LVS (Language Variation Suite). Nine variants of {eung} and six variants of {eo} were observed in the data. Regression analyses showed that ‘discourse function’ of {eung} and {eo} was the primary constraint influencing the variation examined. Age was analyzed as another statistically significant factor: Older people used {eung} variants more often than younger people. This result may be taken to indicate either age grading or linguistic change in progress; further research based on careful methodology is in order for its accurate interpretation.